Click on a lesson name to select. Population Biology Lesson 6.

Post on 17-Jan-2016

217 Views

Category:

Documents

0 Downloads

Preview:

Click to see full reader

Transcript

Click on a lesson name to select.

Population Biology

Lesson 6

Click on a lesson name to select.

Warm Up

Essential Question:

How do abiotic and biotic factors affect population size?

Objective:SWBAT explain how abiotic and biotic factors affect population size.

Do Now:1.Explain the difference between the transfer of matter and energy through an

ecosystem.

Lesson Overview

Agenda•Discussion: Population Ecology

Homework•Population Dynamics Reading and Vocabulary

Population Density

The number of organisms per unit area

Population Dynamics

Spatial Distribution

Chapter 4 Population Ecology

Dispersion is the pattern of spacing of a population.

Population Ecology

Population Dynamics

Common dolphin

Pupfish

A species might not be able to expand its population range because it cannot survive the abiotic conditions found in the expanded region.

Population Ranges

Chapter 4

6

Population Dynamics• Limiting Factors: Biotic or abiotic

factors that restrict or prevent the existence, numbers, reproduction, or distribution of organisms.– Ex. A predator such as a lynx is a

limiting factor for a prey such as a hare.

– Ex. A cold snowy winter is a limiting factor for thousands of species that would die under those conditions.

– Ex. In brackish water, fish can’t pass from salt water to fresh water. The salinity of the water is a limiting factor.

http://www.yukonman.com/pictures2-8.asp

http://www.fotosearch.com/COR356/110000/

Population Ecology

Population-Limiting Factors

Population Dynamics

There are two categories of limiting factors—density-independent factors and density-dependent factors.

Chapter 4

Density-Independent Factors Any factor in the environment that does

not depend on the number of members in a population per unit area is a density-independent factor.

Population Ecology

Weather events Fire Human alterations of the landscape Air, land, and water pollution

Population Dynamics

Chapter 4

Density-Dependent Factors

Any factor in the environment that depends on the number of members in a population per unit area is a density-dependent factor.

Population Ecology

Biotic factors Disease Competition Parasites

Population Dynamics

Chapter 4

Population Biology

Population Ecology

Carrying Capacity

The maximum number of individuals in a species that an environment can support for the long term is the carrying capacity.

Carrying capacity is limited by the energy, water, oxygen, and nutrients available.

Chapter 4

11

Population Dynamics• Competition: A density-dependent factor.

Individuals competing for limited resources like – food – space

– mates• Competition leads to a limited amount of

resources available to all individual in a population.

• As a population nears carrying capacity competition increases.

• Competition is a density-dependent limiting factor.

Population Ecology

Population Growth Rate

The population growth rate (PGR) explains how fast a given population grows.

The natality of a population is the birthrate in a given time period.

Population Dynamics

Chapter 4

Population Ecology

Exponential Growth Model

Exponential growth occurs when the growth rate is proportional to the size of the population.

All populations grow exponentially untilsome limiting factor slows the population’s growth.

Population Dynamics

Chapter 4

Population Ecology

Logistic Growth Model

The population’s growth slows or stops following exponential growth, at the population’s carrying capacity.

Population Dynamics

Chapter 4

Human Population Growth

The study of human population size, density, distribution, movement, and birth and death rates is demography.

4.2 Human Population

Population EcologyChapter 4

Technological Advances

For thousands of years, environmental conditions kept the size of the human population at a relatively constant number below the environment’s carrying capacity.

Population Ecology

Humans have learned to alter the environment in ways that appear to have changed its carrying capacity.

Human Population

Chapter 4

Human Carrying Capacity

Population Ecology

Scientists are concerned about the human population reaching or exceeding the carrying capacity.

An important factor is the amount of resources from the biosphere that are used by each person.

Human Population

Chapter 4

What is population density?

Population EcologyChapter 4

Chapter Diagnostic Questions

B. number of organisms in an area

C. characteristics of a population

D. manner in which a population grows

A. pattern of spacing of a population inan area

Which is a density-dependent factor?

A. disease

B. fire

C. flooding

D. weather

Population EcologyChapter 4

4.1 Formative Questions

Which is a density-independent factor?

A. competition

B. extreme cold

C. parasites

D. predation

Population EcologyChapter 4

4.1 Formative Questions

Which factor can limit the carrying capacity of a population?

A. emigration

B. predation

C. available nutrients

D. extreme temperatures

Population EcologyChapter 4

4.1 Formative Questions

The study of the size, density, distribution, and movement of the human population is _______.

A. bioinformatics

B. demography

C. ecology

D. ethnography

Population EcologyChapter 4

4.2 Formative Questions

Which is a primary reason for the decline in the percent growth of the human population after 1962?

A. decreased agriculture

B. famine and wars

C. setbacks in medicine

Population EcologyChapter 4

4.2 Formative Questions

D. voluntary populationcontrol

A. exponential

B. spatial

C. genetic

D. logistic

Which type of population growth model does this graph represent?

Population EcologyChapter 4

Chapter Assessment Questions

top related